Mid-range and distant vehicle detection with a mobile camera

We present a method to detect vehicles in image sequences without pre-knowledge about the position of the road. Image data is provided by a single camera placed in a moving vehicle. To detect mid-range and distant vehicles we use a combination of three different clues. First, we select regions in the image plane that exhibit the characteristics of shadow projected underneath a vehicle. Then, we analyse the entropy and horizontal symmetry of these selected regions. Only those regions that contain enough entropy and symmetry are identified as potential vehicles. We test our algorithm by means of many different experiments, all based on practical video data recorded under different circumstances. These experiments illustrate the robust and accurate performance of our detection method.